PAM2800VINABR

High Power White LED Driver PAM2800 F eatures n n n n n n n n n High Efficiency 92% Up to 350mA Constant Source Current Low Quiescent Current: Typ. 65 μ A 0.5 μ A Shutdown Current Short Circuit Protection Open Load LED Protection Thermal Protection Space Saving Package SOT23-5 Pb-Free Package General Descriptio n The PAM2800 is a high power white LED driver with 350mA constant rated source current. It features high efficiency and low quiescent current, making it ideal for battery powered applications. Applications n High Power White LED Driver Typical Application Circuit Efficiency vs Supply Voltage 100 IN VIN Efficiency(%) VOUT PAM2800 EN GND FB C IN 1μF 95 R1 CO 2.2 μ F 90 85 80 75 70 RS R2 1W WLED 65 60 4.8 4.5 4.2 3.9 3.6 3.3 Supply Voltage(V) Figure 1 Power Analog Microelectronics , Inc www.poweranalog.com 09/2008 Rev 1.1 1 High Power White LED Driver P in Configuration & Marking Information Top View SOT23-5 5 EG I Y W PAM2800 4 EG: I: Y: W: Product Code of PAM2800 Current Code Year Week 1 2 3 Pin Number 1 2 3 4 5 Name VIN GND EN FB VOUT Function Input Ground Chip Enable (Active High) Feedback Output Power Analog Microelectronics , Inc www.poweranalog.com 09/2008 Rev 1.1 2 High Power White LED Driver A bsolute Maximum Ratings PAM2800 These are stress ratings only and functional operation is not implied . Exposure to absolute maximum ratings for prolonged time periods may affect device reliability . All voltages are with respect to ground . Input Voltage..............................................6.6V Output Current........................................350mA Output Pin Voltage...............GND -0.3to V IN+0.3V Lead Soldering Temperature (5sec)...........300 ° C Storage Temperature...................-65 ° C to 150 ° C Recommended Operating Conditions Max. Supply Voltage (for Max. duration of 30 minutes)..............................................6.4V Junction Temperature.................-40 ° C to 125 ° C Ambient Temperature...................-40 ° C to 85 ° C Thermal Information Parameter Thermal Resistance (Junction to Case) Thermal Resistance (Junction to Ambient) Internal Power Dissipation Symbol θJC θJA PD Package SOT23-5 SOT23-5 SOT23-5 Maximum 130 250 400 Unit °C/W mW Electrical Characteristic T A=25 ° C , V IN=3.7V, C IN=1 μ F, C O=2.2 μ F, unless otherwise noted . Parameter Input Voltage Output Current Quiescent Current Efficiency Over Temperature Shutdown Over Temperature Hysteresis OTS OTH IO=1mA IO=1mA Symbol VIN IO IQ No Load 90 300 65 92 150 30 90 Test Conditions Min Typ Max 5.5 Unit V mA μA % °C °C Power Analog Microelectronics , Inc www.poweranalog.com 09/2008 Rev 1.1 3 High Power White LED Driver Typical Performance Characteristics T A=25°C,C IN=1 μ F,C O=2.2 μ F,R1=62k Ω, R2=33k Ω ,R S=0.22 Ω. Efficiency vs Supply Voltage 100 95 90 PAM2800 Output Current vs Supply Voltage 400 350 Output Current(mA) Efficiency(%) 85 80 75 70 65 60 4.8 4.5 4.2 3.9 3.6 3.3 Supply Voltage(V) 300 250 200 150 100 4.8 4.5 4.2 3.9 3.6 3.3 Supply Voltage(V) Power Analog Microelectronics , Inc www.poweranalog.com 09/2008 Rev 1.1 4 High Power White LED Driver A pplication Information In the typical application (see Figure 1), the LED current will come to constant current level little by little after the device is powered. A 62ΚΩ resistor is recommended for R1, and the value for R2 should be adjusted around 33ΚΩ due to LED forward voltage variation from lot-to-lot or brandto-brand. Power Dissipation and Thermal Consideration Thermal protection limits power dissipation in the PA M 2 8 0 0 . W h e n t h e o p e r a t i o n j u n c t i o n temperature exceeds 150°C, the OTP (Over Temperature Protection) starts the thermal shutdown and turns the pass transistor off. The pass transistor resumes operation after the junction temperature drops below 120°C. For continuous operation, the junction temperature should be maintained below 125°C. The power dissipation is defined as: P D= (V IN-V OUT)*I O+V IN*I GND The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surrounding airflow and temperature difference between junction and ambient. The maximum power dissipation can be calculated by the following formula: P D(MAX) = (T J(MAX)-T A)/θ JA Where T J(MAX) is the maximum operation junction temperature 125°C.TA is the ambient temperature, and θ JA is the thermal resistance from the junction to the ambient. For example, as θ JA is 250°C/W for SOT-23, based on the standard JEDEC 51-3 for a singlelayer thermal test board, the maximum power dissipation for SOT-23 package at T A=25°C can be calculated by following formula: P D(MAX)= (125°C-25°C)/250=0.4W To calculate the junction temperature of the PAM2800 SOT-23 package, if we use input voltage V IN=4V at an output current I O=300mA and the case temperature T A=40°C measured by the thermal couple while operating, the power dissipation is defined as: P D=(4V-2.8V)*300mA+4V*70μA≈360mW PAM2800 Power Analog Microelectronics , Inc www.poweranalog.com 09/2008 Rev 1.1 5 High Power White LED Driver O rdering Information PAM2800 PAM2800 X X X X Shipping Package Number of Pins Package Type Pin Configuration Pin Configuration A Type 1. VIN 2. GND 3. EN 4. FB 5. VOUT Package Type A ：SOT-23 Number of Pins B：5 Shipping Package R：Tape & Reel Part Number PAM2800AABR Output Current 350mA Marking EGAYW Package Type SOT23-5 MOQ 3,000 Units/Tape&Reel Power Analog Microelectronics , Inc www.poweranalog.com 09/2008 Rev 1.1 6 High Power White LED Driver O utline Dimension c (REF.) 0.25 θ L REF. L1 (REF.) PAM2800 SOT23-5 D e1 E1 E REF. A A1 A2 c D E E1 L L1 θ b e e1 Min 0 0.70 2.70 2.60 1.40 0º 0.30 Millimeter Nom 1.10MAX 0.05 1.00 0.12REF. 2.90 2.80 1.60 0.45REF. 0.60REF. 5º 0.40 0.95REF. 1.90REF. A1 A2 A Max 0.10 1.295 3.10 3.00 1.80 10º 0.50 Power Analog Microelectronics , Inc www.poweranalog.com 09/2008 Rev 1.1 7